Container weighing machine with buoyant liquid weighing medium



May 27, 1952 R. E. J. NQRDQUIST 2,597,894

CONTAINER WEIGHING MACHINE WITH BUOYANT LIQUID WEIGHING MEDIUM FiledDec. 3o, 1949 4 sheets-sheet i l FQ INVEN TOR.

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A TTOENEYS May 27, 1952 R. E. J. NoRDQUlsT 2,597,894

CONTAINER WEIGHING MACHINE WITH BUOYANT LIQUID WEIGHING MEDIUM FiledDec. .'50, 1949 4 Sheets-Sheet 2 INVENTOR.

EON/9L@ E. J.' /VOEQU/S T ATTORNEYS May 27 1952 R. E. J. NQRDQUIST2,597,894

CONTAINER WEIGHING MACHINE WITH BUOYANT LIQUID WEIGHING MEDIUM FiledDeo. 50, 1949 4 Sheefcs-Sheet -5 ZM f May 27, 1952 R. E.A J. NoRDQUlsT2,597,894

CONTAINER WEIGHING MACHINE WITH BUOYANT LIQUID WEIGHING MEDIUM FiledDec. 30, 1949 4 Sheets-Sheet 4 l l I I lr 11./ mf# V INVENTOR.

60N/)LD EJI /VOEDOU/ST ATTORNEYS Patented May 27, 1952 CONTAINERWEIGHING MACHINE WITH VBUOYAN'I LIQUID WEIGHING MEDIUM Y Ronald E. J.Nordquist, Maplewood, N.` J., as-

signorto American Can Company, New York, N.' Y., a corporation of NewJersey Application December 30, 1949, Serial No. 135,931

8 Claims. AL1

The presenti-mentionrelates generally to machines for weighing lledcontainersv or cans and has particular referenceto devices for detectingand-segregating underweightcans through their buoyancyiin a liquidWeighing. medium.

I An objectof `Vthe instant. invention is the provision a icanweighing:machine of devices wherein lightweight orxunderilled cans may bereadily detected and segregated from full weight cans.

Another .object is the provision of such a Weighing-machinewherein aliquid weighing medium is usedto; effectif-rapid and accurate detectionof lightweight cans through buoyancy of they-cans when immersed intheliquid medium.

Anotherobject isthe `provision of such a Weighing machine ywhich issimple-in construction and economical':infmaintenance and operation and`which -is readily adapted to weighing cans moving in a= continuous-procession in spaced and timed order.

Numerous other objects and advantages of the invention will be apparentas it is better understood 4Vfromk the I following description, which,takenv inv connection with the accompanying drawings, discloses apreferred embodiment thereof.

- Referring tothe drawings:

Figure l. isua'longitudinal sectional View of a weighingfmachineembodying the instant invention, with parts broken away;

Fig. 2 is a wiring diagram of the electric apparatususedin themachine;

Fig. Sis an enlarged sectional viewtaken substantially/ along the-brokenline 3--3 .in Fig. 1. with parts broken away;

l- Fig; 4: is :an enlarged sectional Aview taken substantially alongthev line 4-3-4iin Fig. 1, with parts broken away;

'f-istan ,enlargedfview Vof a portion of a bucket conveyor used Yin themachine, with parts broken away and parts shown in` section;

, Fig; 6is a fragmentary top plan View of the conveyor shown in Fig'. 5;

' Fig. 'Z'is apviewsimilar toxFig. 4 and shows a modifledform'of theinvention; and

tlfis an enlarged sectional view taken substantially along Vthe line8--8 in Fig. 7.

As a preferred or exemplary embodiment cf thetinstant invention, Figures1 to 6 inclusive of thedrawings'illustrate a machine Afor weighingfilled andsealedgsheetfmetal.cans A moving in Spacect-:andtimed;;ordenina. continuous procession,..-.As.the.nl1edl more .along a straightlnefpathgoftravel-theyfsare .immersed in a liquid Shaft 35;.

'insufficiently filled and therefore will belightin weight as comparedto a properly lled can. Such a lightweight can is buoyed up bythe brinesolution and projects above the position of a properly filled can. Henceas theccans are. conveyed subsequently through a detecting station, `thelightweight cans, project abnormally above the full weight cans, and arereadily detected and subsequently segregated from thefull weight cans.

In the machine, the cans A to be weighed are received from anysuitablesource of supply, preferably by way of a runway .2 I` ('Fig. l)comprising a plurality of guide rails 22disposed in proper position toguide and permit the cans to roll or slide into the machine. Thezcansare received from the runway 2| individually'in spaced peripheralpockets 24 of a continuously rotating timing turret 25 disposed adjacentthe terminal end of the runway 2| at the entranceend of the machine.Continuations 26 of therails 22 curve around the turret adjacent itsouter periphery and hold the cans in the turret pockets.

The turret .25 is mounted on a shaft 21 journaled in a pair of spacedbearing brackets 28 carried on a frame 29. which `constitutes the mainframe ofthe machine. The turret is rotated by a gear 3| vwhich ismounted on oneV end ofthe shaft 21. The gear 3| in turniis rotated by apair of meshing idler gears 32 mounted on. shortl shafts carriedin thebracket 28. These idler gears are driven by a gear '33;carriedon anidlerfshaft 34 of a continuously moving weighing conveyor 35.-

Through this gear.train.theitiming-turret 25 is rotated in time withtheconveyor.

- The weighing conveyor :35 extends substantially thefull'length ofthe/machine in a horizontal position and comprises a pair ofspaced andparallel endless chains 31. The, chains 31- arev composed of relativelylong links 38 (see Figs. 5 and 6) connected at their ends by pins 4|lwhich'carry actuating rollers 42. These conveyor chains 31 are operatedin unison by a pair of spaced idler discs 45 (Fig. 1) and a pair ofspaced' driving discs 45, the discs being providedwith peripheralnotches Y 151 for engaging the rollers 42 and thus serving as sprocketsfor driving the chains.

The idler discs or; sprockets 45am-located at the entrance' end of Athemachine adjacent the' timing turret` 25- and. .are mounted on the `idlerThe shaft ris, journaledin a pair of spaced bearing blocks 49 which arebolted to the main frame 29. The driving discs or sprockets 46 arelocated at the discharge end of the machine and are mounted on a maindriving shaft 5I which is journaled in a pair of spaced bearing blocks52 bolted to the main frame 29. The driving shaft 5l is the main drivingshaft of the machine and may be rotated in any suitable manner.

The discs or sprockets 435, 46 are disposed in a vertical position sothat the conveyor chains 31 between the sprockets operate alonghorizontal upper and lower runs. The chains 37 along their upper runsare supported against sagging between the sprockets d5, E6 by a pair ofhorizontal tracks 54 (Figs. 1, 3 and 4) having straight parallel grooves55 in which the rollers 42 operate as they move between the sprockets.'These tracks are supported on brackets 56 which are bolted to the mainframe 29.

Between the conveyor chains 3l, each pair of opposing links 38 of thechains, support a weighing bucket 6l (Figs. l, 3, 4, 5 and 6). The endsof the buckets are secured, preferably by welding, to the chain links.Each bucket, as viewed in Figs. 4 and 5, are formed with straightvertical side walls and end walls, a rounded or curved bottom to fit acan, and an open top, the walls and bottom of the bucket setting off anopen receptacle 62 slightly larger in inside dimensions than a can A forthe reception of the can. One end of each bucket 6| is formed with avertical partition 63 (Figs. 4, 5 and 6) which stops short of the bottomof the bucket and which sets off in the end of the bucket a liquid llingchannel 64 which is open at its outer end and in communication with thecan receptacle 62 atl its inner end.

Hence as the conveyor 35 operates, it carries the weighing buckets 6|,one secured to each opposing pair of chain links 38, in a continuousprocession around the conveyor discs or sprockets 45, 46 and along theupper and lower runs of the conveyor system. As a bucket (ilV travels uparound the idler discs 45 it passes adjacent the timing turret and thisturret, advancing a can A in time with the travel of the conveyor, dropsthe can A into the moving bucket. Pairs of spaced lugs 65 formed on theinside of the bottom of the bucket near the ends of the can receptacleengage the end seams of the can and locate the can in the receptacle sothat it is just below the top edge of the bucket and hold it away fromthe walls of the bucket. Continued advancement of the conveyor carriesthe bucket 6| and the can A retained therein along the upper run of theconveyor system, the track 54 supporting the bucket and its can againstsagging.

During advancement of the bucket `6l and its can A valong the upper runof the conveyor the bucket is lled through its channel 64, with theliquid weighing medium. For this purpose the advancing bucket passesunder a covered tank 61 (Figs. l and 3) which contains a supply of theliquid weighing medium. This tank 61 is disposed above the upper run ofthe conveyor 35 and is formed with supporting legs 68 which are boltedto the tracks 54. The bottom of the tank is formed with a dependingoutlet nozzle 69 which terminates close to and in alignment with theouter open ends of the channels 64 of the moving buckets 6 I. The liquidweighing medium preferably flows continuously from the nozzle 69. Henceas a bucket 6l passes under the nozzle, the liquid medium flows throughthe channel BB 4 into the bucket 6I and fills the can receptacle 62 tothe height of the open end of the channel 5t. The height of the open endof the channel 5t is disposed slightly below the top of bucket 6I toprevent overflowing of the liquid weighing medium from the bucket (seeFigs. 3 and 4).

Replenishment of the liquid weighing medium in the tank 61 is effectedcontinuously by a feed pipe 'H (Fig. 1), one end of which communicateswith the tank near its top. The opposite end oi the pipe communicateswith a continuously driven pump 12 which is connected by a short pipe 13to an open top reservoir 'M located below the tank 61 and under thelower run of the conveyor 35. The pump is driven in any suitable manner.The reservoir contains a large supply of the liquid weighingv medium andis supported on the main frame 29. The reservoir is formed with a drippan 15 which extends under the full length of the conveyor and connectswith the reservoir to drain back into the reservoir any excess liquidmedium from the buckets and the tank nozzle 69.

The liquid weighing medium lled into the bucket 6I immediately reacts onthe can A carried therein in accordance with the weight of the can. Ifthe can is properly filled it weighs a predetermined amount and remainssubmerged in the liquid weighing medium. However if the can isinsuiciently filled, its light weight is not suiiicient to hold itsubmerged and therefore the can will be buoyed up by the liquid weighingmedium and will project above the top of the bucket. Such a buoyed upcan is an abnormal or` lightweight can.

Abnormal or lightweight cans A are detected in any suitable manner andare segregated from the full weight cans near the discharge end of themachine. For this purpose the conveyor 35 carries the buckets 5l whilestill supported by the tracks 54, past a. detecting station B (Fig. l).At this station a beam of light C (Fig. 4) is continuously projectedacross the path of travel of the conveyor 35 immediately above the upperedge of the buckets 6I. This beam of light is supplied from a lamp 8l(Fig. 2) enclosed in a housing S2 (Fig. 4) secured to one of the tracks511. An aperture or slit in the housing forms the light beam. On theopposite side of the conveyor, an electric eye 83 (Fig. 2) is providedto receivev the beam of light. This electric eye is housed in a casing84 (Fig. 4) which is secured to the adjacent track 54.

The electric eye 83 is connected by wires 35, 8l' (Fig. 2) to acommercial or conventionalhigh frequency amplier 88 receiving electriccurrent by way of wires B9, 90 leading to and fromany suitable source ofelectric power. The lamp Si is connected by wires 92, S3 to the powerwires S9, 90 within the amplifier unit. The amplier unit 88 includes aconventional time delay device which is connected by wires 94, to anelectric solenoid 98 of a normally open relay switch 57. The switch isprovided with a pair of terminals, one of which is connected by a wire98 to a normally de-energized electromagnet 99. The other terminal ofthe switch is connected by a wire l0! to a source of electric current182 which in turn is connected by a wire |03 to the electromagnet 99.

The electromagnet S9 (see Fig. l) is located adjacent the conveyordriving disc 46 at the discharge end of the machine and is disposedabove and close to the upper -run of the conveyor 35.

Hence, when the conveyor V35 moves a bucket 6| containing an underlledcan A, through the detector station -B, the underiilled can-projectsalcovel the path of travel of the beam of light C and` therebymomentarily cuts of the light to the electricl eye `233. The electriceye thereupon acts upon the time delay device in the amplifier `unit 88and after a predetermined period of time calculated to coincide with thepassage of the abnormal can under the electromagnet 9.13,l energizes thesolenoid 96 and closes the relay switch Si?. The closing of this switchimmediately completes the circuit connecting with the electromagnet 93andV the magnet thereupon becomesv momentarily energized and lifts andholds theA underlled can A in a raised position within its bucket 6 I.

As the bucket El continues along its path of travel it rolls orslidesthe raised underfilled can A along the bottom or the magnet 99 andtransfers it to a closely adjacent magnetic rail l 05 (Fig. l) disposedabove the path of travel of the conveyor. i Theelectromagnet 99thereupon becomes de-energized by an opening of the relayswitch 9'.' soas to be ineffective on the can in the next succeeding bucket l6l unlessthis can is also underlled. The magnetic rail 105 may be a permanentmagnet or a permanently energized electromagnet and constitutes theentrance rail of an undernlled or abnormal can discharge chute H16. Thebucket El propel-s the underfllled can A along the magnetic rail lil-5until the can is fully extractedfrom the bucket by virtue of the bucketpassing around the conveyor driving discs 45. At this point in thetravel of the underlled can, the magnetic rail |05 curves downwardlyinto the chute 185 and thus permits the can to roll or slide by reasonof its own momentum into the discharge chute IGS which carries the canto any suitable place of deposit.

Normal or properly l'led cans A which remain submerged in the buckets 6lpass under the beam of light C as the buckets move through the detestingstation, and therefore have no effect on the electromagnet 9S. Thesenormal cans remain in their buckets, as the buckets pass around theupper portions of the conveyor driving discs i5 and fall from thebuckets when the latter reach a position which permits. the cans to rollout of them. The falling cans are caught in a normal can discharge chutell which keeps them segregated from the abnormal cans and which carriesthem to any suitable. place of deposit. A curved guide rail Aills (Fig.l) disposed adjacent the. peripheries of the conveyor driving discs @iiserves as the bottom rail of the abnormal can discharge chute IlllE andthe entrance guide rail to the normal can discharge chute. As thebuckets 6l pass around the conveyor driving discs l136, the liquidweighing medium used in the buckets, spills out onto the drain pan 'i5and flows back into the reservoir 'I4 for re-use.

As a modied form of the invention, Figs. 7 and 8 of the drawingsillustrate a permanent magnet III secured in the bottom of the buckets6| where it engages and holds the end seam at one end of a can depositedin a bucket. This manner of holding one end of the can increases thebuoying powei` of the liquid weighing medium when acting on cans whichare only slightly underfilled. In such cans the contents of the canssettle into the held end and leaves a greater empty space at the freeend. Thus the free end projects higher above the bucket and facilitatesdetection by the light beam C. This is particularly an advantage inweighing cans where the degree of lightweight is only slightly belowfull weight.

'.It. vis thought that .the invention and many of its attendantadvantageswillbe understood from the.- foregoing description, and itwill be apparent thatl various changes may he made in the form,construction and arrangement of the parts without departing fromthespirit and scope of the invention or sacrificing all of its materialadvantages, the. form hereinbefore described being merely a preferred:embodiment thereof.

I claim:

1. In a machine )for Weighing lled and sealed containers todifferentiate underlled from properlyiilled.. containers,v thecombination of a conveyorqincluding a pair of spaced chains havinglinks.: .rollers Vcarried .by said links on the outsider' of.. saidchains. buckets. extending betweenand mounted on said chains, eachbucket having a receptacle. for holding a container, said buckethaving.a llng channel communicating with: said receptacle, a horizontal trackfor said conveyor rollers for'holdingsaid buckets in a horizonal`position,` and; means for :filling each horizontal bncket;..throughsaid filling channel with a liquid weighing medium for surrounding thecontainer in said. bucket receptacle, said liquidfmedium buoying uplightweight containers: so that. they project above the weighing mediumvto indicate .their underfllled condition.

v2. In. amachine -for weighing filled and sealed containers todifferentiate underlled from properly:lleducontainers, .the combinationof an endless conveyor, spaced' sprockets for supportingandvforactuating said conveyor, a horizontal track forguding one run of theconveyor between `said sprockets, a plurality of buckets carried by saidconveyor, each of .said buckets havinge.; receptacle for: holdingacontainer while the bucketsf..aremoving along said horizontal track,-a'container .timing and feeding device disposed adjacent :the first ofsaid sprockets for depositing:` a.` container into the receptacle ofeach ofwsaid bucketsasr the buckets move horizontally, a tank containinga supply of liquid weighingmedium disposed between said sprockets. andabove. the-path of .travel of said buckets forzlling each of saidreceptacles with said liquid weighing medium as each bucket passes said:tank-.whereby lightweight containers are buoyedzup. above.- theweighing medium in their receptacles` to. indicate their underlledcondition.

3. :In a: machine forweighingfilled and sealed containersfin liquidato.segregate underlled containers from properly lled containers bydetection of their relative buoyancy, the combination of an endlessconveyor having a horizontal run, a plurality of buckets carried by saidconveyor and being open at the top while passing along the horizontalrun of the conveyor, each bucket at that time receiving and holding acontainer to be weighed, means for filling said open top buckets with aliquid Weighing medium to surround the container, said lightweightcontainers riding higher in the liquid by reason of their greaterbuoyancy, and means for removing said elevated containers from theirbuckets to segregate the underlled and the properly lled containers.

4. In a machine for weighing lled and sealed containers to differentiateunderfilled from properly lled containers, the combination of an endlessconveyor having a horizontal run, means for actuating said conveyor, aplurality of buckets carried by said conveyor, each of said buckets whenon the upper run of said conveyor being open at the top, means forplacing a sealed container in each open top bucket, means for nlling aliquid weighing medium into a bucket and around the container thereinfor buoying up lightweight containers so that-they project further abovethe Weighing medium to indicate their underlled condition, means fordetecting the projecting lightweight containers, and segregating meansoperable by said detecting means for segregating the underlledcontainers from the properly filled containers.

5. In a machine for Weighing filled and sealed containers todifferentiate underlled from properly lled containers, the combinationof an endless conveyor, means for actuating said conveyor, a pluralityof buckets carried by said conveyor, each of said buckets having, areceptacle for holding a container, asupply tank located at a higherlevel than said buckets, .said tank having an outlet disposed aboveA thepath of said buckets for discharging liquidweighing medium into eachpassing receptacle to surround the container therein for buoying uplightweight containers to an elevated level so that they project abovethe Weighing medium to indicate their underlled condition, means forretaining said illed buckets in a liquid holding position, a beam oflight projected across and above the path of travel of said buckets andnormally received by an electric eye disposed in alignment with saidbeam of light, and segregating means operated by said electric eye .whensaid light beam is intercepted by a passing elevated `lightweightcontainer for segregating the underlled containers from the properlylled containers as detected by said beam of light.

6. In a machine for weighing filled and sealed containers todiierentiate underlled from properly filled containers, the combinationof an endless conveyor, means for actuating said conveyor, a pluralityof buckets carried by said conveyor, each of said buckets having areceptacle for holding a container, said bucket also having a liquidlling channel spaced from and in communication with its containerreceptacle, a supply tank located at a higher level than said conveyorbuckets, said tank having an outlet located above the path of travel ofthe bucket filling channels for discharging a liquid weighing mediuminto each passing bucket receptacle and around the container for buoyingup lightweight containers so that they project at a higher level abovethe Weighing medium to indicate their underlled condition, means Afordetecting the projecting lightweight containers, Van underlled containerdischarge chute and a properly lled container discharge chute disposedadjacent the path of travel of said buckets for selectively receivingthe corresponding container, and magnetic means disposed at saidunderiilled container discharge chute and operable by said detectingmeans for removing detected lightweight containers from theirreceptacles for placing them into said underfilled container dischargechute to segregate the underfilled containers from the properly lled andnon-detected containers.

7. In a machine for weighing filled and sealed containers todiierentiate underlled from properly iilled containers, the combinationof a receptacle for holding a container, a liquid weighing mediumdisposed in said receptacle for buoying up lightweight containers sothat they project above the weighing medium to indicate theirunderfllled condition, and means disposed in said receptacle for holdingone end of the container submerged in said liquid weighing medium tofacilitate projection of the free end of a lightweight container abovethe weighing medium.

8. In a machine for Weighing filled and sealed containers todifferentiate underlled from properly lled containers the combination ofa receptacle for holding a container, a liquid weighing medium disposedin said receptacle for buoying up lightweight containers so that theyproject above the weighing medium to indicate their underiilledcondition, and magnet means disposed in said receptacle and engageableby one end of the container for holding said end submerged in saidliquid Weighing medium to facilitate projection of the free end of alightweight container` above the Weighing medium.

RONALD E. J. NORDQUIST.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 529,188 Pike Nov. 13, 18941,524,928 Hardel et al. Feb. 3, 1925 1,572,055 Warren Feb. 9, 19262,142,920 Rose Jan. 3, 1939 2,176,784 Bowden Oct. 17, 1939 2,235,725Nordquest Mar. 18, 1941 2,263,811 Lipkin Nov. 25, 1941

